AWD Transmission: AOC oil and filter change.

[niguk68]

Hi all, I have just done this on my 2004 xc70.
I have uploaded to a gallery. I will do a write up when I have time. The pictures will give you the general idea.


gallery: http://www.volvoforums.org.uk/vbpicg...do=view&g=2465

parts: http://www.volvoforums.org.uk/vbpicg...do=view&g=2466

[Georgeandkira]

Hello, What does AOC mean? Is it the new bevel gear? I can't think of anything which has an oil pump except the engine. Kira

[niguk68]

Hi, it stands for active on demand coupling. It is fitted to XC70 after I think 2001 and xc90's. It is made by haldex and replaces the viscus coupling on the v70 awd. Its basically and electronic clutch that changes how much power gets sent to the rear wheels. the pump runs all the time, charging an accumilator, so when the clutch is needed it can react in fractions of a second.
The best place to learn about it is on Haldex's web site under AWD. The AOC is bolted to the rear differential and the bevel gear is at the front bolted to the gearbox.

[niguk68]

First I would like to say this was more difficult than I had thought. I am a time served mechanic of 25 years and have tools that most diyers will not have so I will try to be as specific as I can.

1. Remove negative battery terminal. If you don't have access to a vehicle lift or pit (which is best) then get your XC well jacked up safely on axle stands and I also put blocks under the rear wheels as well. Chock the front wheels and put in park or gear. Remember safety first, you are a long time dead.
2. I sugest removing the exhaust first as I didn't and struggled. It was much easyer putting it back together getting access to the propshaft bolts.
3. Remove the electrical plugs and the 2 x 4mm allen screws that hold on the haldex control box or DEM box as volvo call it.
4. Mark your propshaft and flange so when you re-fit it can go back in the same place. Remove the 6 x allen bolts that hold on the rear of the propshaft. Then find an m8 bolt x 20mm. On the back of the propshaft flange you will see 4 x extra m8 bolt holts (see pic in gallery). These are for pushing out the propshaft CV joint centre. I did it with just 1 bolt very carefully, but you may need to put at least 2. It all depends how stuck fast yours is.
5. Next remove the 4 x bolts from the propshaft centre bearing and let the propshaft down to the floor. If you are on a lift or over a pit I sugest tieing some string and supporting it. The heat shield will need to have the small plastic clips removed to allow this. Also forgot to say to support your cat exhaust on the flexi joint.
6. The next thing is to remove the 24mm nut that holds the propshaft flange to the AOC. I also marked the nut and shaft so as to try and tighten it to the same place when re-building. I used an air wrench to remove it. But i'm sure if you could hold the flange with say a filter strap you could get it undone.
7. Mark the flange and centre. I suggest the use of a puller to get the flange off. I very gently warmed mine with a blow lamp testing how hot it was getting from the back so as to not damage the oil seal. Then hit it from the rear with a suitable hammer and punch. (This is not good becasue you are so close to the electronic terminals of the pressure sensor). Best to get a puller if you can. Oil will run out once the flange is removed.
8. You now have access to the pump and oil filter. Remove the 2 x allen bolts on both and gently prise out. The filter will just come out because there is a spring between the cover and the filter.
9. I went for my dinner and let the oil drain out. Approx 1 hour.
10. wipe out the holes. don't be tempted to use an airline as this might blow particles into the ports of your AOC.
11. Clean off the pump, same again wipe.
12. fit new style filter. (see gallery)
13. Re- fit pump
14. Fill with volvo AOC oil. I used an old atf bottle. I managed to get 400mls in it but I suspect thats because the car is jacked up. I will remove the bung again on the level.
15. Re-fit the prop flange taking cared to align your marks. Fit nut and tighten. Mine went back slightly tighter than my mark.
16. Re-fit prop same again aligning your marks, tighten each bolt a small amount so it pulls the cv joint centre back in gradually. check and double check those bolts
17. re-fit DEM module.
18. re-fit exhaust.
Thats it, Battery lead back on, switch back on and listen for pump going.
Take for a test drive and when you get back look for oil leaks.
I hope its a long time before I have to do this again, but I have a friend with an xc70 and I'm sure I will end up doing it as well.
Also the old oil was much thicker than the new and it has blobs of what looked like litium grease (see pic) but that was all no metal or hard bits.
Have fun.
Niguk68.

[andymuggwump]

Hi,

Thanks for the great write up. My car was experiencing the same issues as your, no AWD and 000B code stored. I have cleared the code and it hasn't returned....yet. I would like to do the oil and filter change but having read your write up it seems very tricky. I don't suppose you fancy doing the job on my XC90, paid of course?
Andy

[niguk68]

Originally Posted by andymuggwump

Hi,

Thanks for the great write up. My car was experiencing the same issues as your, no AWD and 000B code stored. I have cleared the code and it hasn't returned....yet. I would like to do the oil and filter change but having read your write up it seems very tricky. I don't suppose you fancy doing the job on my XC90, paid of course?
Andy

Hi, sorry for the late reply. If you still want it doing, personal message me your telephone number and I'll see what I can do.
Niguk.

[Gazdok]

Hello niguk68,

This is a very nice write up. I am planning on doing this on a V70 AWD from 2006.
I guess underneath the car it will be pretty much like yours.
I read through VIDA instructions on how to do this.

Did you get the exhaust off easy, i.e. did the 2 bolts come out or did you have to cut them off? You wrote you left it on, but the pictures show that you took it off ib the end.

Did you fill the prop flange with grease when you refitted it?

Did you have to fill any more AOC oil in? VIDA says 500 to 600 ml should go in there.

Actually did you do this just for maintainance or because you had a problem with the AWD?

[Gazdok]

Hi niguk68,

PM sent

[niguk68]

Originally Posted by Gazdok

Hello niguk68,

This is a very nice write up. I am planning on doing this on a V70 AWD from 2006.
I guess underneath the car it will be pretty much like yours.
I read through VIDA instructions on how to do this.

Did you get the exhaust off easy, i.e. did the 2 bolts come out or did you have to cut them off? You wrote you left it on, but the pictures show that you took it off ib the end.

Did you fill the prop flange with grease when you refitted it?

Did you have to fill any more AOC oil in? VIDA says 500 to 600 ml should go in there.

Actually did you do this just for maintainance or because you had a problem with the AWD?

Hi, I did try PMing you but I havn't got 30 posts yet so I will reply here.
The flange has extra holes for you to put m8 bolts in (see pics) and shove the prop out of the tight fitting flange. The bolts need to be quite short.

My exhaust bolts were just on the point of not getting them off.
Did not grease the flange as it is meant to be a tight fit. but can't see any reason why not.
It did take a little more oil when I filled it to the level hole while jacked up but when I had the car level it came out and probably ended up with approx 600ml.
I did this for both, had a problem related to it not working (fault code) once cleared worked fine. But while looking into the problem found out about it not having an oil change so decided to do it as a precaution.

[Gazdok]

I have just done a oil and filter change on my V70 AWD. While I found niguk68's write up extremely helpful, I seemed to get stuck despite following VIDA and niguk68.
I added some hints in red to niguk68:
All this can be done even by a skilled DIYer with normal garage / DIY tools.

Originally Posted by niguk68

1. Remove negative battery terminal. If you don't have access to a vehicle lift or pit (which is best) then get your XC well jacked up safely on axle stands and I also put blocks under the rear wheels as well. Chock the front wheels and put in park or gear. Remember safety first, you are a long time dead.
2. I sugest removing the exhaust first as I didn't and struggled. It was much easyer putting it back together getting access to the propshaft bolts. I removed the exhaust after first trying to do it without. If you have a DPF the prop shaft does not come down without the exhaust removed and lowered.
3. Remove the electrical plugs and the 2 x 4mm allen screws that hold on the haldex control box or DEM box as volvo call it.
4. Mark your propshaft and flange so when you re-fit it can go back in the same place. Remove the 6 x allen bolts that hold on the rear of the propshaft. Then find an m8 bolt x 20mm. On the back of the propshaft flange you will see 4 x extra m8 bolt holts (see pic in gallery). These are for pushing out the propshaft CV joint centre. I did it with just 1 bolt very carefully, but you may need to put at least 2. It all depends how stuck fast yours is.
5. Next remove the 4 x bolts from the propshaft centre bearing and let the propshaft down to the floor. If you are on a lift or over a pit I sugest tieing some string and supporting it. The heat shield will need to have the small plastic clips removed to allow this. Also forgot to say to support your cat exhaust on the flexi joint.
6. The next thing is to remove the 24mm nut that holds the propshaft flange to the AOC. I also marked the nut and shaft so as to try and tighten it to the same place when re-building. I used an air wrench to remove it. But i'm sure if you could hold the flange with say a filter strap you could get it undone.
I put two screwdrivers through holes in the flange from front to back to stop the flange rotating. Just be careful not to damage some bits behind the flange if a screwdriver slips.
7. Mark the flange and centre. I suggest the use of a puller to get the flange off. I very gently warmed mine with a blow lamp testing how hot it was getting from the back so as to not damage the oil seal. Then hit it from the rear with a suitable hammer and punch. (This is not good because you are so close to the electronic terminals of the pressure sensor). Best to get a puller if you can. Oil will run out once the flange is removed.
Mine came out with a couple a gentle knocks with a long chisel. But mind the DEM sensor and choke valve if you have not removed them.
8. You now have access to the pump and oil filter. Remove the 2 x allen bolts on both and gently prise out. The filter will just come out because there is a spring between the cover and the filter.
9. I went for my dinner and let the oil drain out. Approx 1 hour.
10. wipe out the holes. don't be tempted to use an airline as this might blow particles into the ports of your AOC.
11. Clean off the pump, same again wipe.
12. fit new style filter. (see gallery)
13. Re- fit pump
14. Fill with volvo AOC oil. I used an old atf bottle. I managed to get 400mls in it but I suspect thats because the car is jacked up. I will remove the bung again on the level.
15. Re-fit the prop flange taking cared to align your marks. Fit nut and tighten. Mine went back slightly tighter than my mark.
16. Re-fit prop same again aligning your marks, tighten each bolt a small amount so it pulls the cv joint centre back in gradually. check and double check those bolts
17. re-fit DEM module.
18. re-fit exhaust.
I put stainless steel bolts in and painted them with heat resistant aluminium exhaust paint in the hope that next time I will not have to get them off with a hack saw.
Thats it, Battery lead back on, switch back on and listen for pump going.
Take for a test drive and when you get back look for oil leaks.
I hope its a long time before I have to do this again, but I have a friend with an xc70 and I'm sure I will end up doing it as well.
Also the old oil was much thicker than the new and it has blobs of what looked like litium grease (see pic) but that was all no metal or hard bits.
Have fun.
Niguk68.